The first combined experimental and theoretical study on the ionization and lipophilic properties of peptide nucleic acid(PNA)derivatives,including eleven PNA monomers and two PNA decamers,is described.The acidity con...The first combined experimental and theoretical study on the ionization and lipophilic properties of peptide nucleic acid(PNA)derivatives,including eleven PNA monomers and two PNA decamers,is described.The acidity constants(pKa)of individual acidic and basic centers of PNA monomers were measured by automated potentiometric pH titrations in water/methanol solution,and these values were found to be in agreement with those obtained by MoKa software.These results indicate that single nucleobases do not change their pKa values when included in PNA monomers and oligomers.In addition,immobilized artificial membrane chromatography was employed to evaluate the lipophilic properties of PNA monomers and oligomers,which showed the PNA derivatives had poor affinity towards membrane phospholipids,and confirmed their scarce cell penetrating ability.Overall,our study not only is of potential relevance to evaluate the pharmacokinetic properties of PNA,but also constitutes a reliable basis to properly modify PNA to obtain mimics with enhanced cell penetration properties.展开更多
To investigate the effects of anti-sense peptide nucleic acids (PNAs) targeting Ki-67 gene on modulation of the proliferation and apoptosis of human renal carcinoma cell lines, human renal carcinoma cell line 786-0 ...To investigate the effects of anti-sense peptide nucleic acids (PNAs) targeting Ki-67 gene on modulation of the proliferation and apoptosis of human renal carcinoma cell lines, human renal carcinoma cell line 786-0 cells were treated with anti-sense PNAs at different concentrations (1.0 μmol/L, 2.0 μmol/L, 10.0 μmol/L). The Ki-67 expression of 786-0 cells was detected by immunohistochemical technique and Western blot method respectively. The proliferation of 786-0 cells was studied by cell growth curves and ^3H-thymidine incorporation. The apoptosis of 786-0 cells was detected by TUNEL assay. The control groups were treated with anti-sense oligonucleotide (ASODNs) targeting Ki-67 gene. Our results showed that the Ki-67 expression of 786-0 cells treated with anti-sense PNAs (16.9±0.7) was significantly inhibited as compared with that of the control groups (28.6±0.4) (P〈0.01). The Ki-67 protein rate of 786-0 cells treated with anti-sense PNAs (42.1 ±2.2) was significantly reduced when compared with that of the control groups (83.6± 1.4) (P〈0.01). Proliferation of 786-0 cells treated with anti-sense PNAs (20.7 ± 1.5) was significantly inhibited as compared with that of the control groups (58.6± 1.4) (P〈0.01). The apoptosis rate of 786-0 cells treated with anti-sense PNAs (28.7 ± 2.3) was significantly increased higher compared with that of the control groups (13.8 ±1.0) (P〈0.01). From these finds we are led to conclude that anti-sense PNAs targeting Ki-67 gene have stronger effects on the inhibition of the proliferation and induction of apoptosis of human renal carcinoma cells than ASODNs targeting Ki-67 gene. The strategies using anti-sense PNAs targeting Ki-67 gene may be a promising approach for the treatment of renal cell carcinoma.展开更多
Protected (L) and (D)-lysine were used respectively as starting materials to synthesize two new types of chiral blocks for the construction of PNA. Nucleobase was linked to alpha-NH2 of lysine via -CH2C (O)- spacer in...Protected (L) and (D)-lysine were used respectively as starting materials to synthesize two new types of chiral blocks for the construction of PNA. Nucleobase was linked to alpha-NH2 of lysine via -CH2C (O)- spacer in type I, and -C (O)- was used in type II. The corresponding oligomers were constructed in solution.展开更多
<em>Background:</em> Antisense peptide nucleic acids (PNAs) exhibit growth inhibitory effects on bacteria by inhibiting the expression of essential genes and could be promising therapeutic agents for treat...<em>Background:</em> Antisense peptide nucleic acids (PNAs) exhibit growth inhibitory effects on bacteria by inhibiting the expression of essential genes and could be promising therapeutic agents for treating bacterial infections. A study was carried out to determine the efficacy of several antisense PNAs in inhibiting extracellular and intracellular growth of <em>Mycobacterium smegmatis</em>. <em>Methods: </em>Six PNAs obtained from a commercial supplier were tested to evaluate the inhibitory effect on bacterial growth by inhibiting the expression of the following essential genes: <em>inhA </em>(a fatty acid elongase), <em>rpsL</em> (ribosomal S12 protein), <em>gyrA</em> (DNA gyrase), <em>pncA</em> (pyrazinamidase), <em>polA</em> (DNA polymerase I) and <em>rpoC</em> (RNA polymerase <em>β</em> subunit) of <em>M. smegmatis</em>. Each PNA was tested at 20 μM, 10 μM, 5 μM and 2.5 μM concentrations to determine whether they caused a dose dependent killing of <em>M. smegmatis</em> cultured in Middlebrook 7H9 broth or in a J774A.1 murine macrophage cell line.<em> Results:</em> In Middlebrook broth, the strong growth inhibitory effect against <em>M. smegmatis</em> was observed by PNAs targeting the <em>inhA </em>and <em>rpsL</em> genes at all four concentrations. The PNAs targeting the<em> pncA</em>, <em>polA</em> and<em> rpoC</em> genes were found to exhibit strong growth inhibition against <em>M. smegmatis</em> but only at 20 μM concentration. No growth inhibition of <em>M. smegmatis </em>was seen in pure culture when treated with PNAs targeting gyrA and a mismatch PNA targeting dnaG (DNA primase). All six PNAs showed killing of <em>M. smegmatis </em>in J774A.1 macrophage cell line that were statistically significant (p < 0.05). <em>Conclusion:</em> It may be concluded from this study that PNAs could be potential therapeutics for mycobacterial infections.展开更多
The massive global spread of the COVID-19 pandemic makes the development of more effective and easily popularized assays critical.Here,we developed an ultrasensitive nanomechanical method based on microcantilever arra...The massive global spread of the COVID-19 pandemic makes the development of more effective and easily popularized assays critical.Here,we developed an ultrasensitive nanomechanical method based on microcantilever array and peptide nucleic acid(PNA)for the detection of severe acute respiratory syndrome-coronavirus-2(SARS-CoV-2)RNA.The method has an extremely low detection limit of 0.1 fM(105 copies/mL)for N-gene specific sequence(20 bp).Interestingly,it was further found that the detection limit of N gene(pharyngeal swab sample)was even lower,reaching 50 copies/mL.The large size of the N gene dramatically enhances the sensitivity of the nanomechanical sensor by up to three orders of magnitude.The detection limit of this amplification-free assay method is an order of magnitude lower than RT-PCR(500 copies/mL)that requires amplification.The non-specific signal in the assay is eliminated by the in-situ comparison of the array,reducing the false-positive misdiagnosis rate.The method is amplification-free and label-free,allowing for accurate diagnosis within 1 h.The strong specificity and ultrasensitivity allow single base mutations in viruses to be distinguished even at very low concentrations.Also,the method remains sensitive to fM magnitude lung cancer marker(miRNA-155).Therefore,this ultrasensitive,amplification-free and inexpensive assay is expected to be used for the early diagnosis of COVID-19 patients and to be extended as a broad detection tool.展开更多
Background Peptide nucleic acid (PNA) has many characteristics useful in molecular biology. This paper described an effective way to raise the cell ingestion rate of PNA so as to kill gastric cancer cells. Methods H...Background Peptide nucleic acid (PNA) has many characteristics useful in molecular biology. This paper described an effective way to raise the cell ingestion rate of PNA so as to kill gastric cancer cells. Methods Heteroduplexes of PNAs and oligonucleotides, wrapped by Lipofectamine 2000, were used to infect SGC7901 cells. The inhibitive effect of heteroduplexes was evaluated by analyzing cell clone forming and cell growth rate. Telomerase activity of SGC7901 cells was detected by polymerase chain reaction enzyme-linked immunosorbent assay (PCR-ELISA) and silver staining assay.Results PNAs showed a dose-dependent inhibition of cell proliferation. The percentage of proliferation inhibition was 99.4% after 7 days; the rate of cloning inhibition was 98.2% after 8 days; whereas for oligonucleotide groups, at the same concentration, the percentages were 50.1% and 67.5% respectively. Antisense PNA-DNA-Lipofectamine 2000 group (AP-D-L group) exhibited significantly different percentages from the control groups (P<0.05). The test result indicated that telomerase activity of the AP-D-L group was inhibited (P<0.05). At the same time, the impact on cell morphology was observed. Conclusions The results showed that PNAs are potent antisense reagents. The telomerase-associated therapies are very promising for the treatment of malignant tumours.展开更多
N-Boc protected amino acids of analogues of peptide nucleic add (PNA), which are a class of conformationally constrained building blocks based on 4-aminoproline backbone with chirality at 2-C and 4-C, have been synthe...N-Boc protected amino acids of analogues of peptide nucleic add (PNA), which are a class of conformationally constrained building blocks based on 4-aminoproline backbone with chirality at 2-C and 4-C, have been synthesized. Those monomers can be used for the construction of novel peptide nucleic acid analogues.展开更多
A large and incremental number of non-coding RNAs, including microRNAs (miRNAs) have been recently demonstrated to play a very important role in human pathologies, including cancer. Therefore, microRNAs have been prop...A large and incremental number of non-coding RNAs, including microRNAs (miRNAs) have been recently demonstrated to play a very important role in human pathologies, including cancer. Therefore, microRNAs have been proposed as therapeutic targets and molecules exhibiting anti-miRNA activity or mimicking functional miRNAs have been developed. Among biomolecules proposed in anti-miRNA therapy, peptide nucleic acids (PNAs) are appealing, in consideration of their stability and efficacy in recognizing RNA targets. PNAs against tumor associated miRNAs have proven to be efficient in inducing anti-tumor effects both in vitro and in vivo. For instance, PNAs targeting miR-155-5p are able to induce apoptosis in glioma cell lines and to enhance the sensitivity to temozolomide (TMZ) in TMZ resistant glioma cells. In vivo, PNAs anti-miR-21 were found to exhibit anti-tumor effects associated with improved survival when administered to animals with intracranial gliomas.展开更多
The synthesis of peptoid nucleic acid bearing thymine as nucleobase has been achieved. This modified oligonucleotide showed good hybridization with DNA.
A novel artificial site specific cleavage reagent, with peptide nucleic acid (PNA) as sequence-recognizing moiety and cerium (IV) ions as “scissors” for cleaving target DNA, was synthesized. Subsequently, it was...A novel artificial site specific cleavage reagent, with peptide nucleic acid (PNA) as sequence-recognizing moiety and cerium (IV) ions as “scissors” for cleaving target DNA, was synthesized. Subsequently, it was employed in the cleavage of target 26-mer single-stranded DNA (ssDNA), which has 10-mer sequence complementary with PNA recognizer in the hybrids, under physiological conditions. Reversed-phase high-performance liquid chromatogram (RPHPLC) experiments indicated that the artificial site specific cleavage reagent could cleave the target DNA specifically.展开更多
Objective: To study the differences and similarities of the antisense drugs with different structures on the biological functions of K562 cells. Methods: Cytotoxic effects were measured by use of a cell viability assa...Objective: To study the differences and similarities of the antisense drugs with different structures on the biological functions of K562 cells. Methods: Cytotoxic effects were measured by use of a cell viability assay. Flow cytometric analysis and agarose gel electrophoresis of DNA fragmentation were also performed. The expression level of protein was assayed by immunofluorescence using fluoresce isothiocyanate label. Results: PNA targeting the coding region of the Bcl-2 messenger RNA could effectively inhibit K562 cell viability, down-regulate the synthesis of the Bcl-2 protein and increase cell apoptosis. By 72 h after the Bcl-2 antisense PNA treatment, K562 cells showed more reduction in the level of Bcl-2 protein compared with cells treated with the antisense ODN. After treatment with 10 μmol/L of Bcl-2 antisense PNA or antisense ODN for 72 h, apoptotic rates of K562 cells were 13.15±1.13 and 11.72±1.12, respectively. Furthermore, there was significant difference in the percentage of apoptotic cells between antisense PNA group and antisense ODN group. Conclusion: The results suggest that antisense PNA targeting the coding region of Bcl-2 mRNA has better antisense effects than the antisense oligonucleotides on inducing apoptosis of K562 cells. Key words Bcl-2 - Antisense peptide nucleic acid - Antisense oligonucleotide - K562 cells - Apoptosis CLC number Q255 Foundation item: This work was supported by the Key Foundation of Science & Technology Program of Guangzhou (No.2001-Z-037-01), and the Nature Science Key Foundation of Guangdong Province (No. 021195).Biography: LEI Xiao-yong(1970–), male, associate professor, doctor of medicine, Institute of Pharmacy and Pharmacology, Nanhua University, majors in tumor pharmacology.展开更多
Photonic crystals(PCs)exhibit promising structural coloration properties and possess extensive application prospects in diverse optical fields.However,state-of-the-art inorganic or polymeric PCs show limited adaptivit...Photonic crystals(PCs)exhibit promising structural coloration properties and possess extensive application prospects in diverse optical fields.However,state-of-the-art inorganic or polymeric PCs show limited adaptivity as their configurations are fixed once formed.Herein,bio-organic adaptive PCs are fabricated via drop-casting of amphiphilic guanine-based peptide nucleic acid selfassembled microspheres.The high formation activation energy of up to 81.8 kJ·mol−1 suggests that the self-assembly step dominates the entire process.Therefore,the configurations along with the structural coloration of the supramolecular PCs are sensitive to self-assembly influencing parameters,showing temperature-encoded structural color evolution and solvent polaritydependent solvatochromism.Our findings demonstrate that the supramolecular PCs are adaptive,thus showing promising potential for detection of organic solvents of different polarities in a visual and real-time manner for environmental protection or optical applications.展开更多
基金Pramod Thakare thanks the University of Milan for the Ph.D.fellowship.Giulia Caron,Maura Vallaro and Sonja Visentin acknowledge the financial support from the University of Turin(Ricerca Locale ex-60%,Bando2019).
文摘The first combined experimental and theoretical study on the ionization and lipophilic properties of peptide nucleic acid(PNA)derivatives,including eleven PNA monomers and two PNA decamers,is described.The acidity constants(pKa)of individual acidic and basic centers of PNA monomers were measured by automated potentiometric pH titrations in water/methanol solution,and these values were found to be in agreement with those obtained by MoKa software.These results indicate that single nucleobases do not change their pKa values when included in PNA monomers and oligomers.In addition,immobilized artificial membrane chromatography was employed to evaluate the lipophilic properties of PNA monomers and oligomers,which showed the PNA derivatives had poor affinity towards membrane phospholipids,and confirmed their scarce cell penetrating ability.Overall,our study not only is of potential relevance to evaluate the pharmacokinetic properties of PNA,but also constitutes a reliable basis to properly modify PNA to obtain mimics with enhanced cell penetration properties.
基金This project was supported by a grant from the Nature Science Project of Health Bureau of Jiangsu Province (No. H200153).
文摘To investigate the effects of anti-sense peptide nucleic acids (PNAs) targeting Ki-67 gene on modulation of the proliferation and apoptosis of human renal carcinoma cell lines, human renal carcinoma cell line 786-0 cells were treated with anti-sense PNAs at different concentrations (1.0 μmol/L, 2.0 μmol/L, 10.0 μmol/L). The Ki-67 expression of 786-0 cells was detected by immunohistochemical technique and Western blot method respectively. The proliferation of 786-0 cells was studied by cell growth curves and ^3H-thymidine incorporation. The apoptosis of 786-0 cells was detected by TUNEL assay. The control groups were treated with anti-sense oligonucleotide (ASODNs) targeting Ki-67 gene. Our results showed that the Ki-67 expression of 786-0 cells treated with anti-sense PNAs (16.9±0.7) was significantly inhibited as compared with that of the control groups (28.6±0.4) (P〈0.01). The Ki-67 protein rate of 786-0 cells treated with anti-sense PNAs (42.1 ±2.2) was significantly reduced when compared with that of the control groups (83.6± 1.4) (P〈0.01). Proliferation of 786-0 cells treated with anti-sense PNAs (20.7 ± 1.5) was significantly inhibited as compared with that of the control groups (58.6± 1.4) (P〈0.01). The apoptosis rate of 786-0 cells treated with anti-sense PNAs (28.7 ± 2.3) was significantly increased higher compared with that of the control groups (13.8 ±1.0) (P〈0.01). From these finds we are led to conclude that anti-sense PNAs targeting Ki-67 gene have stronger effects on the inhibition of the proliferation and induction of apoptosis of human renal carcinoma cells than ASODNs targeting Ki-67 gene. The strategies using anti-sense PNAs targeting Ki-67 gene may be a promising approach for the treatment of renal cell carcinoma.
文摘Protected (L) and (D)-lysine were used respectively as starting materials to synthesize two new types of chiral blocks for the construction of PNA. Nucleobase was linked to alpha-NH2 of lysine via -CH2C (O)- spacer in type I, and -C (O)- was used in type II. The corresponding oligomers were constructed in solution.
文摘<em>Background:</em> Antisense peptide nucleic acids (PNAs) exhibit growth inhibitory effects on bacteria by inhibiting the expression of essential genes and could be promising therapeutic agents for treating bacterial infections. A study was carried out to determine the efficacy of several antisense PNAs in inhibiting extracellular and intracellular growth of <em>Mycobacterium smegmatis</em>. <em>Methods: </em>Six PNAs obtained from a commercial supplier were tested to evaluate the inhibitory effect on bacterial growth by inhibiting the expression of the following essential genes: <em>inhA </em>(a fatty acid elongase), <em>rpsL</em> (ribosomal S12 protein), <em>gyrA</em> (DNA gyrase), <em>pncA</em> (pyrazinamidase), <em>polA</em> (DNA polymerase I) and <em>rpoC</em> (RNA polymerase <em>β</em> subunit) of <em>M. smegmatis</em>. Each PNA was tested at 20 μM, 10 μM, 5 μM and 2.5 μM concentrations to determine whether they caused a dose dependent killing of <em>M. smegmatis</em> cultured in Middlebrook 7H9 broth or in a J774A.1 murine macrophage cell line.<em> Results:</em> In Middlebrook broth, the strong growth inhibitory effect against <em>M. smegmatis</em> was observed by PNAs targeting the <em>inhA </em>and <em>rpsL</em> genes at all four concentrations. The PNAs targeting the<em> pncA</em>, <em>polA</em> and<em> rpoC</em> genes were found to exhibit strong growth inhibition against <em>M. smegmatis</em> but only at 20 μM concentration. No growth inhibition of <em>M. smegmatis </em>was seen in pure culture when treated with PNAs targeting gyrA and a mismatch PNA targeting dnaG (DNA primase). All six PNAs showed killing of <em>M. smegmatis </em>in J774A.1 macrophage cell line that were statistically significant (p < 0.05). <em>Conclusion:</em> It may be concluded from this study that PNAs could be potential therapeutics for mycobacterial infections.
基金This work was supported by the National Natural Science Foundation of China(Nos.11627803,11872355,and 32061160475)University of Science and Technology of China(USTC)Research Funds of the Double First-Class Initiative(No.YD2480002003).
文摘The massive global spread of the COVID-19 pandemic makes the development of more effective and easily popularized assays critical.Here,we developed an ultrasensitive nanomechanical method based on microcantilever array and peptide nucleic acid(PNA)for the detection of severe acute respiratory syndrome-coronavirus-2(SARS-CoV-2)RNA.The method has an extremely low detection limit of 0.1 fM(105 copies/mL)for N-gene specific sequence(20 bp).Interestingly,it was further found that the detection limit of N gene(pharyngeal swab sample)was even lower,reaching 50 copies/mL.The large size of the N gene dramatically enhances the sensitivity of the nanomechanical sensor by up to three orders of magnitude.The detection limit of this amplification-free assay method is an order of magnitude lower than RT-PCR(500 copies/mL)that requires amplification.The non-specific signal in the assay is eliminated by the in-situ comparison of the array,reducing the false-positive misdiagnosis rate.The method is amplification-free and label-free,allowing for accurate diagnosis within 1 h.The strong specificity and ultrasensitivity allow single base mutations in viruses to be distinguished even at very low concentrations.Also,the method remains sensitive to fM magnitude lung cancer marker(miRNA-155).Therefore,this ultrasensitive,amplification-free and inexpensive assay is expected to be used for the early diagnosis of COVID-19 patients and to be extended as a broad detection tool.
基金ThisworkwassupportedbytheProvincialTechnologyCouncilFoundationofHeilongjiang China (No QC0 1C0 8andNo GC0 3C60 5 6)
文摘Background Peptide nucleic acid (PNA) has many characteristics useful in molecular biology. This paper described an effective way to raise the cell ingestion rate of PNA so as to kill gastric cancer cells. Methods Heteroduplexes of PNAs and oligonucleotides, wrapped by Lipofectamine 2000, were used to infect SGC7901 cells. The inhibitive effect of heteroduplexes was evaluated by analyzing cell clone forming and cell growth rate. Telomerase activity of SGC7901 cells was detected by polymerase chain reaction enzyme-linked immunosorbent assay (PCR-ELISA) and silver staining assay.Results PNAs showed a dose-dependent inhibition of cell proliferation. The percentage of proliferation inhibition was 99.4% after 7 days; the rate of cloning inhibition was 98.2% after 8 days; whereas for oligonucleotide groups, at the same concentration, the percentages were 50.1% and 67.5% respectively. Antisense PNA-DNA-Lipofectamine 2000 group (AP-D-L group) exhibited significantly different percentages from the control groups (P<0.05). The test result indicated that telomerase activity of the AP-D-L group was inhibited (P<0.05). At the same time, the impact on cell morphology was observed. Conclusions The results showed that PNAs are potent antisense reagents. The telomerase-associated therapies are very promising for the treatment of malignant tumours.
基金ProjectsupportedbytheNationalNaturalScienceFoundationofChina (No .2 0 172 0 70 )andtheMajorStateBasicResearchDevelopmentPro gram (No .G19985 110 3 )
文摘N-Boc protected amino acids of analogues of peptide nucleic add (PNA), which are a class of conformationally constrained building blocks based on 4-aminoproline backbone with chirality at 2-C and 4-C, have been synthesized. Those monomers can be used for the construction of novel peptide nucleic acid analogues.
基金the European Union(EU)Horizon 2020 Research and Innovation Programme(GA#633937)project ULTRAsensitive PLAsmonic devices for early CAncer Diagnosisby Associazione Italiana per la Ricerca sul Cancro(AIRC)(IG#13575 to RG).This study was also supported by the Interuniversity Consortium for the Biotechnology,Italy
文摘A large and incremental number of non-coding RNAs, including microRNAs (miRNAs) have been recently demonstrated to play a very important role in human pathologies, including cancer. Therefore, microRNAs have been proposed as therapeutic targets and molecules exhibiting anti-miRNA activity or mimicking functional miRNAs have been developed. Among biomolecules proposed in anti-miRNA therapy, peptide nucleic acids (PNAs) are appealing, in consideration of their stability and efficacy in recognizing RNA targets. PNAs against tumor associated miRNAs have proven to be efficient in inducing anti-tumor effects both in vitro and in vivo. For instance, PNAs targeting miR-155-5p are able to induce apoptosis in glioma cell lines and to enhance the sensitivity to temozolomide (TMZ) in TMZ resistant glioma cells. In vivo, PNAs anti-miR-21 were found to exhibit anti-tumor effects associated with improved survival when administered to animals with intracranial gliomas.
基金Authors thank the National NatUral Science Foundation of China for financial support !(29672047).
文摘The synthesis of peptoid nucleic acid bearing thymine as nucleobase has been achieved. This modified oligonucleotide showed good hybridization with DNA.
基金This work was supposed by the National Basic Research Program(973 Program)from the Ministry of Science and Technology of China(G1998051114)the National Natural Science Foundation of China(20272004)
基金This work was supported by the National Natural Science Foundation of China(No.20443005)the Nanotechnology Special Projects of Shanghai(No.0352nm123)
文摘A novel artificial site specific cleavage reagent, with peptide nucleic acid (PNA) as sequence-recognizing moiety and cerium (IV) ions as “scissors” for cleaving target DNA, was synthesized. Subsequently, it was employed in the cleavage of target 26-mer single-stranded DNA (ssDNA), which has 10-mer sequence complementary with PNA recognizer in the hybrids, under physiological conditions. Reversed-phase high-performance liquid chromatogram (RPHPLC) experiments indicated that the artificial site specific cleavage reagent could cleave the target DNA specifically.
基金This work was supported by the KeyFoundation of Science & Technology Program of Guangzhou(No.2001-Z-037-01) and the Nature Science Key Foundationof Guangdong Province (No. 021195).
文摘Objective: To study the differences and similarities of the antisense drugs with different structures on the biological functions of K562 cells. Methods: Cytotoxic effects were measured by use of a cell viability assay. Flow cytometric analysis and agarose gel electrophoresis of DNA fragmentation were also performed. The expression level of protein was assayed by immunofluorescence using fluoresce isothiocyanate label. Results: PNA targeting the coding region of the Bcl-2 messenger RNA could effectively inhibit K562 cell viability, down-regulate the synthesis of the Bcl-2 protein and increase cell apoptosis. By 72 h after the Bcl-2 antisense PNA treatment, K562 cells showed more reduction in the level of Bcl-2 protein compared with cells treated with the antisense ODN. After treatment with 10 μmol/L of Bcl-2 antisense PNA or antisense ODN for 72 h, apoptotic rates of K562 cells were 13.15±1.13 and 11.72±1.12, respectively. Furthermore, there was significant difference in the percentage of apoptotic cells between antisense PNA group and antisense ODN group. Conclusion: The results suggest that antisense PNA targeting the coding region of Bcl-2 mRNA has better antisense effects than the antisense oligonucleotides on inducing apoptosis of K562 cells. Key words Bcl-2 - Antisense peptide nucleic acid - Antisense oligonucleotide - K562 cells - Apoptosis CLC number Q255 Foundation item: This work was supported by the Key Foundation of Science & Technology Program of Guangzhou (No.2001-Z-037-01), and the Nature Science Key Foundation of Guangdong Province (No. 021195).Biography: LEI Xiao-yong(1970–), male, associate professor, doctor of medicine, Institute of Pharmacy and Pharmacology, Nanhua University, majors in tumor pharmacology.
基金the National Key Research and Development Program of China(No.2022YFE0100800)the National Natural Science Foundation of China(No.52175551)。
文摘Photonic crystals(PCs)exhibit promising structural coloration properties and possess extensive application prospects in diverse optical fields.However,state-of-the-art inorganic or polymeric PCs show limited adaptivity as their configurations are fixed once formed.Herein,bio-organic adaptive PCs are fabricated via drop-casting of amphiphilic guanine-based peptide nucleic acid selfassembled microspheres.The high formation activation energy of up to 81.8 kJ·mol−1 suggests that the self-assembly step dominates the entire process.Therefore,the configurations along with the structural coloration of the supramolecular PCs are sensitive to self-assembly influencing parameters,showing temperature-encoded structural color evolution and solvent polaritydependent solvatochromism.Our findings demonstrate that the supramolecular PCs are adaptive,thus showing promising potential for detection of organic solvents of different polarities in a visual and real-time manner for environmental protection or optical applications.