BACKGROUND High-grade B-cell lymphoma(HGBL)is an unusual malignancy that includes myelocytomatosis viral oncogene(MYC),B-cell lymphoma-2(BCL-2),and/or BCL-6 rearrangements,termed double-hit or triple-hit lymphomas,and...BACKGROUND High-grade B-cell lymphoma(HGBL)is an unusual malignancy that includes myelocytomatosis viral oncogene(MYC),B-cell lymphoma-2(BCL-2),and/or BCL-6 rearrangements,termed double-hit or triple-hit lymphomas,and HGBL-not otherwise specific(HGBL-NOS),which are morphologically characteristic of HGBL but lack MYC,BCL-2,or BCL-6 rearrangements.HGBL is partially transformed by follicular lymphoma and other indolent lymphoma,with few cases of marginal zone lymphoma(MZL)transformation.HGBL often has a poor prognosis and intensive therapy is currently mainly advocated,but there is no good treatment for these patients who cannot tolerate chemotherapy.CASE SUMMARY We reported a case of MZL transformed into HGBL-NOS with TP53 mutation and terminal deoxynucleotidyl transferase expression.Gene analysis revealed the gene expression profile was identical in the pre-and post-transformed tissues,suggesting that the two diseases are homologous,not secondary tumors.The chemotherapy was ineffective and the side effect was severe,so we tried combination therapy including venetoclax and obinutuzumab.The patient tolerated treatment well,and reached partial response.The patient had recurrence of hepatocellular carcinoma and died of multifunctional organ failure.He survived for 12 months after diagnosis.CONCLUSION Venetoclax combined with obinutuzumab might improve the survival in some HGBL patients,who are unsuitable for chemotherapy.展开更多
The migrating TdT<sup>+</sup> thymocytes can die in other tissues, promoting the surrounding cells’ renewing likes holocrine secretion does. To clarify the role of TdT-enzyme for this function of progenit...The migrating TdT<sup>+</sup> thymocytes can die in other tissues, promoting the surrounding cells’ renewing likes holocrine secretion does. To clarify the role of TdT-enzyme for this function of progenitor lymphocytes, their extracellular media with its components included by living cells analyzed <em>in vitro</em> before and after<em> in vivo</em> irradiation of donor rats. The nucleoid with DNase-sensitive (free) DNA and TdT activity discovered in extracellular media conditioned preliminary by spontaneous apoptotic death of a minor part of the thymocyte’s suspension <em>in vitro</em>. The penetration of labeled products of non-template synthesis with free DNA’ primers from media into cells by pinocytosis confirmed by exogenous polymeric DNA marked artificially. The DNA penetration into cells follows an increase of the cell’s viability and acceleration of spontaneous intracellular DNA-synthesis controlled with labeled thymidine uptake. Both phenomena are typical for either the lowest initial concentration of intact cells or their preliminary irradiation <em>in vivo</em>. The data point to possible involvement of apoptotic decay of TdT<sup>+</sup> cells in the reutilization of the extracellular DNA fragments for reparation/regeneration of surrounding living cells.展开更多
Alkaline phosphatase(ALP)is widely expressed in human tissues.ALP plays an important role in the dephosphorylation of proteins and nucleic acids.Therefore,quantitative analysis of ALP plays a vital role in disease dia...Alkaline phosphatase(ALP)is widely expressed in human tissues.ALP plays an important role in the dephosphorylation of proteins and nucleic acids.Therefore,quantitative analysis of ALP plays a vital role in disease diagnosis and the development of biological detection methods.Terminal deoxynucleotidyl transferase(TdT)catalyzes continuous polymerization of deoxynucleotide triphosphates at the 30-OH end of single-stranded DNA in the absence of a template.In this study,we developed a highly sensitive and selective method based on TdT and endonuclease Ⅳ(Endo Ⅳ)to quantify ALP activity.After ALP hydrolyzes the 30-PO_(4) end of the substrate and generates 30-OH,TdT can effectively elongate the 30-OH end with deoxynucleotide adenine triphosphate(dATP)and produce a poly A tail,which can be detected by the poly T probes.Endo Ⅳ digests the AP site in poly T probes to generate a fluorescent signal and a new 30-OH end,leading to the generation of exponential fluorescence signal amplification.The substrate for TdT elongation was optimized,and a limit of detection of 4.3×10^(-3) U/L was achieved for ALP by the optimized substrate structure.This method can also detect ALP in the cell lysate of a single cell.This work has potential applications in disease diagnosis and biomedical detection.展开更多
Objective: Considerable evidence has showed that apoptosis is involved in both cancer development and inhibition. A new assay (terminal deoxynucleotidyl tansferase, TdT) was recently reported to have advan tages in ...Objective: Considerable evidence has showed that apoptosis is involved in both cancer development and inhibition. A new assay (terminal deoxynucleotidyl tansferase, TdT) was recently reported to have advan tages in the detection of apoptosis. In this study, this assay was used to investigate antitumor drug induced apoptosis in human cancer cells. Methods: TdT assay, DNA gel electrophoresis, electron and light microscopy were used to observe apoptosis. Results: Our results showed that cisplatin induced apoptosis in both HL 60 and SV40T transformed human bronchial epithelial cells was detected with a good dosage and time response. The occurrence of the apoptosis was preceded by the decrease of bcl 2 mRNA expression. With the TdT assay, apoptotic cells were observed in ovarian tumor of patients treated with carboplatin. Conclusion: TdT assay may be applicable to monitor apoptosis in human cancers induced by chemotherapy, and to evaluate tumor cell response during treatment.展开更多
Terminal deoxynucleotidyl transferase(Td T) has been characterized as template-independent polymerase using single-stranded DNA(ss DNA) as primers to generate random oligonucleotides. However, the extension performanc...Terminal deoxynucleotidyl transferase(Td T) has been characterized as template-independent polymerase using single-stranded DNA(ss DNA) as primers to generate random oligonucleotides. However, the extension performance of Td T to single-stranded RNA(ss RNA) is vague. By systematically comparing and contrasting the performance of Td T-catalyzed ss DNA and ss RNA extension, it is indicated that the catalytic efficiency of ss RNA as primers was about 3 times lower than ss DNA as primers. Collectively, it is believed that understanding the catalytic performance of Td T will help to design the strategy to synthesize chimeric DNA on 3-OH of ss RNA, which becomes invaluable.展开更多
基金Supported by The Lishui Science and Technology Planing Projects,No.2020SJZC048.
文摘BACKGROUND High-grade B-cell lymphoma(HGBL)is an unusual malignancy that includes myelocytomatosis viral oncogene(MYC),B-cell lymphoma-2(BCL-2),and/or BCL-6 rearrangements,termed double-hit or triple-hit lymphomas,and HGBL-not otherwise specific(HGBL-NOS),which are morphologically characteristic of HGBL but lack MYC,BCL-2,or BCL-6 rearrangements.HGBL is partially transformed by follicular lymphoma and other indolent lymphoma,with few cases of marginal zone lymphoma(MZL)transformation.HGBL often has a poor prognosis and intensive therapy is currently mainly advocated,but there is no good treatment for these patients who cannot tolerate chemotherapy.CASE SUMMARY We reported a case of MZL transformed into HGBL-NOS with TP53 mutation and terminal deoxynucleotidyl transferase expression.Gene analysis revealed the gene expression profile was identical in the pre-and post-transformed tissues,suggesting that the two diseases are homologous,not secondary tumors.The chemotherapy was ineffective and the side effect was severe,so we tried combination therapy including venetoclax and obinutuzumab.The patient tolerated treatment well,and reached partial response.The patient had recurrence of hepatocellular carcinoma and died of multifunctional organ failure.He survived for 12 months after diagnosis.CONCLUSION Venetoclax combined with obinutuzumab might improve the survival in some HGBL patients,who are unsuitable for chemotherapy.
文摘The migrating TdT<sup>+</sup> thymocytes can die in other tissues, promoting the surrounding cells’ renewing likes holocrine secretion does. To clarify the role of TdT-enzyme for this function of progenitor lymphocytes, their extracellular media with its components included by living cells analyzed <em>in vitro</em> before and after<em> in vivo</em> irradiation of donor rats. The nucleoid with DNase-sensitive (free) DNA and TdT activity discovered in extracellular media conditioned preliminary by spontaneous apoptotic death of a minor part of the thymocyte’s suspension <em>in vitro</em>. The penetration of labeled products of non-template synthesis with free DNA’ primers from media into cells by pinocytosis confirmed by exogenous polymeric DNA marked artificially. The DNA penetration into cells follows an increase of the cell’s viability and acceleration of spontaneous intracellular DNA-synthesis controlled with labeled thymidine uptake. Both phenomena are typical for either the lowest initial concentration of intact cells or their preliminary irradiation <em>in vivo</em>. The data point to possible involvement of apoptotic decay of TdT<sup>+</sup> cells in the reutilization of the extracellular DNA fragments for reparation/regeneration of surrounding living cells.
基金financially supported by the National Natural Science Foundation of China(Grant No.:21904045)the Fundamental Research Funds for the Central Universities(HUST:Grant No.:2019kfyXJJS169)Training Program of Innovation and Entrepreneurship for Undergraduates of Hubei Province(Grant No.:S202010487225).
文摘Alkaline phosphatase(ALP)is widely expressed in human tissues.ALP plays an important role in the dephosphorylation of proteins and nucleic acids.Therefore,quantitative analysis of ALP plays a vital role in disease diagnosis and the development of biological detection methods.Terminal deoxynucleotidyl transferase(TdT)catalyzes continuous polymerization of deoxynucleotide triphosphates at the 30-OH end of single-stranded DNA in the absence of a template.In this study,we developed a highly sensitive and selective method based on TdT and endonuclease Ⅳ(Endo Ⅳ)to quantify ALP activity.After ALP hydrolyzes the 30-PO_(4) end of the substrate and generates 30-OH,TdT can effectively elongate the 30-OH end with deoxynucleotide adenine triphosphate(dATP)and produce a poly A tail,which can be detected by the poly T probes.Endo Ⅳ digests the AP site in poly T probes to generate a fluorescent signal and a new 30-OH end,leading to the generation of exponential fluorescence signal amplification.The substrate for TdT elongation was optimized,and a limit of detection of 4.3×10^(-3) U/L was achieved for ALP by the optimized substrate structure.This method can also detect ALP in the cell lysate of a single cell.This work has potential applications in disease diagnosis and biomedical detection.
文摘Objective: Considerable evidence has showed that apoptosis is involved in both cancer development and inhibition. A new assay (terminal deoxynucleotidyl tansferase, TdT) was recently reported to have advan tages in the detection of apoptosis. In this study, this assay was used to investigate antitumor drug induced apoptosis in human cancer cells. Methods: TdT assay, DNA gel electrophoresis, electron and light microscopy were used to observe apoptosis. Results: Our results showed that cisplatin induced apoptosis in both HL 60 and SV40T transformed human bronchial epithelial cells was detected with a good dosage and time response. The occurrence of the apoptosis was preceded by the decrease of bcl 2 mRNA expression. With the TdT assay, apoptotic cells were observed in ovarian tumor of patients treated with carboplatin. Conclusion: TdT assay may be applicable to monitor apoptosis in human cancers induced by chemotherapy, and to evaluate tumor cell response during treatment.
基金supported by the National Natural Science Foundation of China (NSFC, Nos. 21927814 and 21772143 to J.Y. Zhang)the National Science Foundation of Tianjin (Nos. 20YDTPJC00090, 19ZXDBSY00070 and 20YFZCSY00990 to X.Q. Gong)。
文摘Terminal deoxynucleotidyl transferase(Td T) has been characterized as template-independent polymerase using single-stranded DNA(ss DNA) as primers to generate random oligonucleotides. However, the extension performance of Td T to single-stranded RNA(ss RNA) is vague. By systematically comparing and contrasting the performance of Td T-catalyzed ss DNA and ss RNA extension, it is indicated that the catalytic efficiency of ss RNA as primers was about 3 times lower than ss DNA as primers. Collectively, it is believed that understanding the catalytic performance of Td T will help to design the strategy to synthesize chimeric DNA on 3-OH of ss RNA, which becomes invaluable.
