The Moore-Penrose inverse of a block k-circulant matrix whose blocks are arbitrary matrices are obtained when k has unit modulus. In the meantime. explicit formulae for finding group inverses of certain specified k-ci...The Moore-Penrose inverse of a block k-circulant matrix whose blocks are arbitrary matrices are obtained when k has unit modulus. In the meantime. explicit formulae for finding group inverses of certain specified k-circulant matrices are also given.展开更多
AIM: To investigate the in vitro antitumor effect of adenovirus-mediated small interfering RNAs (siRNAs) on pancreatic cancer and the associated mechanism. METHODS: A 63-nucleotide (nt) oligonucleotide encoding K-rasv...AIM: To investigate the in vitro antitumor effect of adenovirus-mediated small interfering RNAs (siRNAs) on pancreatic cancer and the associated mechanism. METHODS: A 63-nucleotide (nt) oligonucleotide encoding K-rasval12 and specific siRNA were introduced into pSilencer 3.1-H1, then the H1-RNA promoter and siRNA coding insert were subcloned into pAdTrack to get plasmid pAdTrackH1-Avasval12. After homologous recombination in bacteria and transfections of such plasmids into a mammalian packaging cell line 293, siRNA expressing adenovirus Adh1-K-rasval12 was obtained. Stable suppression of K-rasval12 was detected by Northern blot and Western blot. Apoptosis in Panc-1 cells was detected by flow cytometry. RESULTS: We obtained adenovirus AdHl-K-rasval12 carrying the pSilencer 3.1-H1 cassette, which could mediate gene silencing. Through siRNA targeted K-rasval12, the oncogenic phenotype of cancer cells was reversed. Flow cytometry showed that apoptotic index of Panc-1 cells was significantly higher in the AdH1-K-rasval12-treatment group (18.70% at 72 h post-infection, 49.55% at 96 h post-infection) compared to the control groups (3.47%, 3.98% at 72 and 96 h post-infection of AdH1-empty, respectively; 4.21%, 3.78% at 72 and 96 h post-infection of AdHl-p53, respectively) (P<0.05). CONCLUSION: These results demonstrate that adenoviral vectors can be used to mediate RNA interference (RNAi) to induce persistent loss of functional phenotypes. In gene therapy, the selective down-regulation of only the mutant version of a gene allows for highly specific effects on tumor cells, while leaving the normal cells untouched. In addition, the apoptosis of pancreatic cancer cell line Panc-1 can be induced after AdH1-K-rasval12 infection. This kind of adenovirus based on RNAi might be a promising vector for cancer therapy.展开更多
文摘The Moore-Penrose inverse of a block k-circulant matrix whose blocks are arbitrary matrices are obtained when k has unit modulus. In the meantime. explicit formulae for finding group inverses of certain specified k-circulant matrices are also given.
基金Supported by National Natural Science Foundation of China, No.30271473
文摘AIM: To investigate the in vitro antitumor effect of adenovirus-mediated small interfering RNAs (siRNAs) on pancreatic cancer and the associated mechanism. METHODS: A 63-nucleotide (nt) oligonucleotide encoding K-rasval12 and specific siRNA were introduced into pSilencer 3.1-H1, then the H1-RNA promoter and siRNA coding insert were subcloned into pAdTrack to get plasmid pAdTrackH1-Avasval12. After homologous recombination in bacteria and transfections of such plasmids into a mammalian packaging cell line 293, siRNA expressing adenovirus Adh1-K-rasval12 was obtained. Stable suppression of K-rasval12 was detected by Northern blot and Western blot. Apoptosis in Panc-1 cells was detected by flow cytometry. RESULTS: We obtained adenovirus AdHl-K-rasval12 carrying the pSilencer 3.1-H1 cassette, which could mediate gene silencing. Through siRNA targeted K-rasval12, the oncogenic phenotype of cancer cells was reversed. Flow cytometry showed that apoptotic index of Panc-1 cells was significantly higher in the AdH1-K-rasval12-treatment group (18.70% at 72 h post-infection, 49.55% at 96 h post-infection) compared to the control groups (3.47%, 3.98% at 72 and 96 h post-infection of AdH1-empty, respectively; 4.21%, 3.78% at 72 and 96 h post-infection of AdHl-p53, respectively) (P<0.05). CONCLUSION: These results demonstrate that adenoviral vectors can be used to mediate RNA interference (RNAi) to induce persistent loss of functional phenotypes. In gene therapy, the selective down-regulation of only the mutant version of a gene allows for highly specific effects on tumor cells, while leaving the normal cells untouched. In addition, the apoptosis of pancreatic cancer cell line Panc-1 can be induced after AdH1-K-rasval12 infection. This kind of adenovirus based on RNAi might be a promising vector for cancer therapy.
