三联脆组基因在胰腺癌发生发展中的变化及对其增殖的影响和作用机制的初步探讨
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摘要
近年来胰腺癌的发病率呈不断上升趋势，其恶性程度高、较早转移特
性，缺乏有效的早期诊断以及术后易复发性、预后极差。根本原因在于对胰
腺癌的发生。发展的机理了解甚少，缺乏有效的临床治疗手段。目前，关于
癌基因及抑癌基因在肿瘤发生发展中的作用及其机制的研究是肿瘤基础研
究中的热点。本研究以人胰腺癌标本及胰腺癌株为研究对象，研究了新近
由Ohta发现的三联脆组（FHIT）基因在胰腺癌中的mRNA表达的变化规
律、利用脂质体转染技术研究了FHIT过表达对胰腺癌发生发展的影响并
对其作用机制进行了初步探讨。主要结论如下：
一、运用RT－PCR及Nested-PCR技术研究发现：胰腺癌及癌旁组织中
FHIT cDNA均存在较高的异常率分别为 66．7％和 60％。与正常腺组织均
有显著差异（P＜0．01）其cDNA异常主要在非编码区（外显子2-4）及编码
区外显子5，以一个或数个外显子的丢失为主，FHIT基因的异常和FRA3B
区密切相关。故推测FRA3B区可能存在对致癌因素敏感的特定基因序
列。癌旁组织中 FHIT cDNA的高异常率，提示在组织学正常的胰腺癌切
缘的组织细胞在基因水平上却可能存在异常而比正常细胞更易癌变，这可
能与胰腺癌术后高复发率有关。FHIT基因与胰腺癌的发生发展密切相
关。FHIT基因异常在胰腺的发生发展中起重要作用。有意义的是发现胰
腺癌株1990有FHIT全基因丢失。
二、利用较高转染效率的脂质体介导方法对有FHIT全基因丢失的
一 二 一
1990胰腺癌细胞株进行 FHIT转染。转染后，经 RT－PCR及 Western blot－
ting证实获得阳性克隆，其生长明显受到抑制。转染后的细胞对裸鼠致瘤
性明显受到抑制或消失。结果表明FHIT抑制了胰腺癌的增殖及致瘤性。
TIlT为一抑癌基因。本研究为胰腺癌发生的机理及治疗提供了新的途径
及线索。
三、通过对转染前后细胞形态学的观察，发现转染后细胞凋亡指数明显
高于对照组，凋亡定性分析——琼脂糖凝胶电泳检查到特征性的ndder
带，提示凋亡是FHIT抑制胰腺癌生长的途径。对转染前后细胞内AeA
及 ApA的测定结果为 AoA明显下降，而 ApA有上升，ApA／AfoA之比
变化更为明显，FHIT蛋白为一AoA水解酶，但其抑癌作用并不依赖其水
解活性，故推测 FHIT与 AeA结合，FHIT可能为 AoA的特异性搬运载
体，通过细胞信号传导途径诱导了调亡，同时 AoA及 APA可能是一未被
发现的新的细胞信号传导分子。
Recent the morbidity of pancreatic adenocarcinoma has a tendency to be
increasing. It’s well know that the malignancy of pancreatic adenocarcinoma is
much higher than any other alimentary tract carcinomas, it’s easy for pancre-
atic adenocarcinoma to metaslasize, no validity diagnosis is found for this dis-
ease, with a high relapse after operation, all of which contribate to the poor
prognosis of pancreatic adenocarcinoma. Now, the study of the genes which
are associated with the ctevelopment of carcinoma is becoming the hot spot in
oncology field. The aim of this study is (i) to explore the change regularity of
the FHIT gene in pancreatic adenocarcinoma and their adjacent tissues, (ii)
determine the effect on cell growth and tumorigenicity of FHIT gene in 1990
pancreatic adeno careimoma cell line (iii) to probe the mechanize of FHIT in
suppressing the development of panereatic adenocarcinoma. The results and
conclusions are as following.
1. Using the method of RT-PCR and Nested-PCR the study showed that
the altered frequence of human pancreatic adneocarcinoma and their adjacent
tissues were both high (66.7% and 60%) and were much higher than that of
normal pancreas tissues (P<0. 01). The most common altered region of FHIT
eDNA in the tissues analysed was no coding area exon 2 exon 4 and the first
coding exon 5, the alter about FHIT is usually deleted one or several exon.
The high altered frequence of FHIT is connected closely to the fragile region,
the FRA3B locus. The FRA3B locus may have a special gene sequence suscep-
tible to other agents that interfere with DNA replication, such as nicotine, caf-
feine, alcohol, or other known carcinogens. The high frequence of altered
FHIT in pancreatic adenocarcinoma adjacent tissues implicates that this tissues
are easily oncology leading to the high relapse frequence after operation. So,
FHIT gene plays an important role in the development of pancreatic adenocar-
cinoma. FHIT gene was found lost totally in 1990 cell line.
2. The method of liposome transfection can get a high validity of transfec-
tion. FHIT was tranfected to 1990 cell line in which the FHIT gene was lost
totally. Integration and expression of exogenous FHIT gene were confirmed by
RT-PCR and Western blotting. The growth of 1990 pFHIT was suppressed
clearly and its tumorigericity in nude mice was reliminated or supressed also,
all of which indicated that FHIT suppressed the growth and tumorigenicity of
the panereatic adenocarcinoma cell line and supported FHIT is a tumor sup-
pressor gene. So, a new approach is available to probe the mechanize and ther-
apy protocols about pancreatic adenocarcinoma.
3. When the morphology of 1990 and 1990 pFHIT were evaluated, the
apoptosis in 1990 pFHIT increased clearly. By the analysis of its DNA on a-
garose gel for electrophoresis, the characteristic DNA ladder of 200 bp oc-
curred. It could be spectulated that FHIT suppress the development of paner-
catic adehocarcinoma by the path of apoptosis. The level of Ap3A in 1990
pFHIT decreased clearly than that of 1990. However, the level of Ap4A in
1990 pFHIT increased, the ratio of Ap4A to Ap3A changed more clearly.
FHIT protein is a Ap3A hydrolase l but its suppression on tunror didn, t depend
on its hydrosis active. Taken together, a role for FHIT as a proapototic factor
...
is in agreement with the structura1 and biochedrical studies indicating that
FHIT. Ap3A complex is the active FHIT form involved in cel1ular signaling
linking the induction of apoptosis in 1990 pFHIT celIs
性，缺乏有效的早期诊断以及术后易复发性、预后极差。根本原因在于对胰
腺癌的发生。发展的机理了解甚少，缺乏有效的临床治疗手段。目前，关于
癌基因及抑癌基因在肿瘤发生发展中的作用及其机制的研究是肿瘤基础研
究中的热点。本研究以人胰腺癌标本及胰腺癌株为研究对象，研究了新近
由Ohta发现的三联脆组（FHIT）基因在胰腺癌中的mRNA表达的变化规
律、利用脂质体转染技术研究了FHIT过表达对胰腺癌发生发展的影响并
对其作用机制进行了初步探讨。主要结论如下：
一、运用RT－PCR及Nested-PCR技术研究发现：胰腺癌及癌旁组织中
FHIT cDNA均存在较高的异常率分别为 66．7％和 60％。与正常腺组织均
有显著差异（P＜0．01）其cDNA异常主要在非编码区（外显子2-4）及编码
区外显子5，以一个或数个外显子的丢失为主，FHIT基因的异常和FRA3B
区密切相关。故推测FRA3B区可能存在对致癌因素敏感的特定基因序
列。癌旁组织中 FHIT cDNA的高异常率，提示在组织学正常的胰腺癌切
缘的组织细胞在基因水平上却可能存在异常而比正常细胞更易癌变，这可
能与胰腺癌术后高复发率有关。FHIT基因与胰腺癌的发生发展密切相
关。FHIT基因异常在胰腺的发生发展中起重要作用。有意义的是发现胰
腺癌株1990有FHIT全基因丢失。
二、利用较高转染效率的脂质体介导方法对有FHIT全基因丢失的
一 二 一
1990胰腺癌细胞株进行 FHIT转染。转染后，经 RT－PCR及 Western blot－
ting证实获得阳性克隆，其生长明显受到抑制。转染后的细胞对裸鼠致瘤
性明显受到抑制或消失。结果表明FHIT抑制了胰腺癌的增殖及致瘤性。
TIlT为一抑癌基因。本研究为胰腺癌发生的机理及治疗提供了新的途径
及线索。
三、通过对转染前后细胞形态学的观察，发现转染后细胞凋亡指数明显
高于对照组，凋亡定性分析——琼脂糖凝胶电泳检查到特征性的ndder
带，提示凋亡是FHIT抑制胰腺癌生长的途径。对转染前后细胞内AeA
及 ApA的测定结果为 AoA明显下降，而 ApA有上升，ApA／AfoA之比
变化更为明显，FHIT蛋白为一AoA水解酶，但其抑癌作用并不依赖其水
解活性，故推测 FHIT与 AeA结合，FHIT可能为 AoA的特异性搬运载
体，通过细胞信号传导途径诱导了调亡，同时 AoA及 APA可能是一未被
发现的新的细胞信号传导分子。
Recent the morbidity of pancreatic adenocarcinoma has a tendency to be
increasing. It’s well know that the malignancy of pancreatic adenocarcinoma is
much higher than any other alimentary tract carcinomas, it’s easy for pancre-
atic adenocarcinoma to metaslasize, no validity diagnosis is found for this dis-
ease, with a high relapse after operation, all of which contribate to the poor
prognosis of pancreatic adenocarcinoma. Now, the study of the genes which
are associated with the ctevelopment of carcinoma is becoming the hot spot in
oncology field. The aim of this study is (i) to explore the change regularity of
the FHIT gene in pancreatic adenocarcinoma and their adjacent tissues, (ii)
determine the effect on cell growth and tumorigenicity of FHIT gene in 1990
pancreatic adeno careimoma cell line (iii) to probe the mechanize of FHIT in
suppressing the development of panereatic adenocarcinoma. The results and
conclusions are as following.
1. Using the method of RT-PCR and Nested-PCR the study showed that
the altered frequence of human pancreatic adneocarcinoma and their adjacent
tissues were both high (66.7% and 60%) and were much higher than that of
normal pancreas tissues (P<0. 01). The most common altered region of FHIT
eDNA in the tissues analysed was no coding area exon 2 exon 4 and the first
coding exon 5, the alter about FHIT is usually deleted one or several exon.
The high altered frequence of FHIT is connected closely to the fragile region,
the FRA3B locus. The FRA3B locus may have a special gene sequence suscep-
tible to other agents that interfere with DNA replication, such as nicotine, caf-
feine, alcohol, or other known carcinogens. The high frequence of altered
FHIT in pancreatic adenocarcinoma adjacent tissues implicates that this tissues
are easily oncology leading to the high relapse frequence after operation. So,
FHIT gene plays an important role in the development of pancreatic adenocar-
cinoma. FHIT gene was found lost totally in 1990 cell line.
2. The method of liposome transfection can get a high validity of transfec-
tion. FHIT was tranfected to 1990 cell line in which the FHIT gene was lost
totally. Integration and expression of exogenous FHIT gene were confirmed by
RT-PCR and Western blotting. The growth of 1990 pFHIT was suppressed
clearly and its tumorigericity in nude mice was reliminated or supressed also,
all of which indicated that FHIT suppressed the growth and tumorigenicity of
the panereatic adenocarcinoma cell line and supported FHIT is a tumor sup-
pressor gene. So, a new approach is available to probe the mechanize and ther-
apy protocols about pancreatic adenocarcinoma.
3. When the morphology of 1990 and 1990 pFHIT were evaluated, the
apoptosis in 1990 pFHIT increased clearly. By the analysis of its DNA on a-
garose gel for electrophoresis, the characteristic DNA ladder of 200 bp oc-
curred. It could be spectulated that FHIT suppress the development of paner-
catic adehocarcinoma by the path of apoptosis. The level of Ap3A in 1990
pFHIT decreased clearly than that of 1990. However, the level of Ap4A in
1990 pFHIT increased, the ratio of Ap4A to Ap3A changed more clearly.
FHIT protein is a Ap3A hydrolase l but its suppression on tunror didn, t depend
on its hydrosis active. Taken together, a role for FHIT as a proapototic factor
...
is in agreement with the structura1 and biochedrical studies indicating that
FHIT. Ap3A complex is the active FHIT form involved in cel1ular signaling
linking the induction of apoptosis in 1990 pFHIT celIs
引文
1 Levin DL, Connelly, Edvesa SS, et al. Demographic characteristic of cancer of the pancreas: motality, incidence, and survival Cancer, 1981, 47 (6) : 1456
2 Beazley RM, Cohn I. Update on pancreatic cancer, CA-Cancer-J-Clin, 1988, 38(5) : 310
3 张国治。胰腺癌。见:张宏志等 主编。临床胰腺病学。第一版。江苏:江苏科学技术出版社,1989． 264
4 Gudjonsson B. Cancer of the pancreas, 50 years of surgery. Cancer, 1987, 60(9) : 2284
5 Almoguera C, Shibata D, Forrester K, et al. Most human carcinomas of the exocrine pancreas contain mutant c-k-ras genes, Cell, 1988, 53(4) : 549
6 Smit VTHBMK, Boot AJM, Smits AMM, et al. k-ras condon 12 mutations occur very frequently in pancreatic adenocarcinomas. Nucleic Acid Res, 1988, 16(16) 7773
7 Grunewald K, Lyons J, Frohlich A, et al. High frequency of Ki-ras codon 12 mutations on pancreatic adenocarcinomas. Int J Cancer, 43(6) : 1037
8 Ohta M, Inone H, Cotticclli MG, et al. The FHIT gene, spanning the chromosome 3pl4． 2 fragile site and renal carcinoma-associated t(3: 8) breakpoint, is abnormal in digestive tract cancers. Cell, 1996, 84: 587
9 Sozzi G, Veronese M, Negrini, et al. The FHIT gene at 3p14． 2 is abnormal in lung cancer. Cell, 1996, 85;17
10 Virgilio L, Shuster M, Gollin Sm, et al. FHIT gene alterations in head and neck squamous cell carcinomas. Proc Natl Acad Sci USA, 1996, 93: 9770
11 Kastury K, Baffa R, Druck T, et al. Potential gastro-intestinal tumor suppressor locus at the 3pl4． 2 FRA3B site identified by homozygous deletions in tumor cell lines. Cancer Res, 1996, 56: 978
12 Shridhar R, Shridhar V, Wang XH, et al. Frequent breakpoint in the 3pl4． 2 fragile site, FRA3B, in pancreatic tumors. Cancer Res, 1996, 56: 4347
13 Siprashvili Z, Sozzi G, Barnes LD, et al. Replacement of FHIT in cancer cells suppresses tumorigenicity. Proc Natl Acad Sci USA, 1997, 94; 13771
14 Barnes Lo. PN Garrison, Z Siprashvili, et al. FHIT a pntative tumor suppress in human, is a dinucleoside 5',5"-P~1,P~3-triphosphate hydrolase. Biochemistry, 1996, 35: 11529
15 Helen C, Pace, Preston N, et al. Genetic, biochemical, and crystallo-graphic characterization of FHIT-substrate complexes as the active signaling form of FHIT. Proc Natl Acad Sci USA, 1998, 95． 5484
16 Felgne PL, Gadek TR, Holm M, et al. Lipofectin: a highly effecient, lipid-mediated DNA-transfection procedure. Proc Natl Acad Sci USA, 1987, 84: 7413
17 Sozzi G, Veronese M, Negrini, et al. The FHIT gene at 3pl4． 2 is abnormal in lung cancer. Cell, 1996, 85: 17
18 Virgilio L, Shuster M, Gollin SM, et al. FHIT gene alterations in head and neck squamous cell carcinomas. Proc Natl Acad Sci USA, 1996, 93:
9770
19 李卫东,王秀琴,程贵余,等。脆性组胺酸三联体基因与食管癌遗传易感性的关系初探。中华肿瘤杂志,1998,20(4) :258
20 Han HJ, Yanagisana A, Kato Y, et al. Genetic instability in pancreatic cancer and poorly differentiated type of gastaic cancer. Cancer Res, 1993, 53: 5087
21 Thiagalingam S, Lisitsyn NA, Hamaguchi M, et al. Evalution of the FHIT gene in colorectal cancers. Cancer Res, 1996, 56: 2996
22 Huebrer K, Hadaczek P, Siprashvili Z, et al. The FHIT gene, a multiple tumor suppressor gene encompassing the carcinogen sensitive Chromosome fragile site, FRA3B Biochim Biophys Acta, 1997, 1332: M65
23 Huebner K, Sozzi G, Brenner C, Pierotti MA, et al. FHIT loss in lung cancer: diagnostic and therapeutic implications. Adv Oncol, 1999, 15:3
24 Boldog FL, Geminill RM, West J, et al. Chromosome 3pl4 homozygous deletions and sequence analysis of FRA3B. Hum Mol Genet, 1997, 6: 193
25 Nelson HH, Wiencke JK, Gunnl, et al. Chromosome 3pl4 alteration in lung cancer: Evidence that FHIT exon deletion is a target of tobacco carcinogens and asbestos. Cancer Res, 1998, 58: 1804
26 Inoue H, Ishii H, Alder H, et al. Sequence of the FRA3B Common fragile region: implications for the mechanisms of FHIT deletion. Proc Natl Acad Sci USA, 1997, 94: 14584
27 Sozzi G, Tomielli S, Tagliabue E, et al. Absence of FHIT protein in primary lung tumors and cell lines with FHIT gene abnormalities. Cancer Res, 1997, 57: 5207
28 Hadaczok P, Siqrashvili Z, Markiewski M, et al. Absence or reduction
of FHIT expression in most clear cell renal careinomas. Cancer Res, 1998, 58: 2946
29 Mao L, Lee JS, Kurie JM, et al. Clonal genetic alterations in the lungs of current and former smokers. J Natl Cancer Inst, 1997, 89: 857
30 dayman GL, Liu TJ, Overholt SM, et al. Gene therapy for head and neck cancer; comparing the tumor suppressor gene p53 and a cell cycle regulator WAF1/CIP1 (p21) . Arch Otolaryngol. Head Neck Surg, 1996, 122: 489
31 Wang XW, Harris CC, TP53 tumor suppressor gene: clues to molecular carcino genesis and cancer therapy (Review). Cancer Surv, 1996, 28: 169
32 Amalia Vartanian, Ivan Alexandrov, Igor Prudowski, et al. AP_4A induces apoptosis in human caltured cells. FEBS Letter, 1999, 456: 175
33 Zamecnik P, Stephenson M. The role of nucleotides for the function and conformation of enzymes. Munksgoard Copenhagen, 1996． 276
34 Kisselev LL, Just Justesen, Alexey D, et al. Diadenosine oligophosphate (ApnA), a novel class of signalling molecules? FEBS Letters, 1998, 427: 157
2 Beazley RM, Cohn I. Update on pancreatic cancer, CA-Cancer-J-Clin, 1988, 38(5) : 310
3 张国治。胰腺癌。见:张宏志等 主编。临床胰腺病学。第一版。江苏:江苏科学技术出版社,1989． 264
4 Gudjonsson B. Cancer of the pancreas, 50 years of surgery. Cancer, 1987, 60(9) : 2284
5 Almoguera C, Shibata D, Forrester K, et al. Most human carcinomas of the exocrine pancreas contain mutant c-k-ras genes, Cell, 1988, 53(4) : 549
6 Smit VTHBMK, Boot AJM, Smits AMM, et al. k-ras condon 12 mutations occur very frequently in pancreatic adenocarcinomas. Nucleic Acid Res, 1988, 16(16) 7773
7 Grunewald K, Lyons J, Frohlich A, et al. High frequency of Ki-ras codon 12 mutations on pancreatic adenocarcinomas. Int J Cancer, 43(6) : 1037
8 Ohta M, Inone H, Cotticclli MG, et al. The FHIT gene, spanning the chromosome 3pl4． 2 fragile site and renal carcinoma-associated t(3: 8) breakpoint, is abnormal in digestive tract cancers. Cell, 1996, 84: 587
9 Sozzi G, Veronese M, Negrini, et al. The FHIT gene at 3p14． 2 is abnormal in lung cancer. Cell, 1996, 85;17
10 Virgilio L, Shuster M, Gollin Sm, et al. FHIT gene alterations in head and neck squamous cell carcinomas. Proc Natl Acad Sci USA, 1996, 93: 9770
11 Kastury K, Baffa R, Druck T, et al. Potential gastro-intestinal tumor suppressor locus at the 3pl4． 2 FRA3B site identified by homozygous deletions in tumor cell lines. Cancer Res, 1996, 56: 978
12 Shridhar R, Shridhar V, Wang XH, et al. Frequent breakpoint in the 3pl4． 2 fragile site, FRA3B, in pancreatic tumors. Cancer Res, 1996, 56: 4347
13 Siprashvili Z, Sozzi G, Barnes LD, et al. Replacement of FHIT in cancer cells suppresses tumorigenicity. Proc Natl Acad Sci USA, 1997, 94; 13771
14 Barnes Lo. PN Garrison, Z Siprashvili, et al. FHIT a pntative tumor suppress in human, is a dinucleoside 5',5"-P~1,P~3-triphosphate hydrolase. Biochemistry, 1996, 35: 11529
15 Helen C, Pace, Preston N, et al. Genetic, biochemical, and crystallo-graphic characterization of FHIT-substrate complexes as the active signaling form of FHIT. Proc Natl Acad Sci USA, 1998, 95． 5484
16 Felgne PL, Gadek TR, Holm M, et al. Lipofectin: a highly effecient, lipid-mediated DNA-transfection procedure. Proc Natl Acad Sci USA, 1987, 84: 7413
17 Sozzi G, Veronese M, Negrini, et al. The FHIT gene at 3pl4． 2 is abnormal in lung cancer. Cell, 1996, 85: 17
18 Virgilio L, Shuster M, Gollin SM, et al. FHIT gene alterations in head and neck squamous cell carcinomas. Proc Natl Acad Sci USA, 1996, 93:
9770
19 李卫东,王秀琴,程贵余,等。脆性组胺酸三联体基因与食管癌遗传易感性的关系初探。中华肿瘤杂志,1998,20(4) :258
20 Han HJ, Yanagisana A, Kato Y, et al. Genetic instability in pancreatic cancer and poorly differentiated type of gastaic cancer. Cancer Res, 1993, 53: 5087
21 Thiagalingam S, Lisitsyn NA, Hamaguchi M, et al. Evalution of the FHIT gene in colorectal cancers. Cancer Res, 1996, 56: 2996
22 Huebrer K, Hadaczek P, Siprashvili Z, et al. The FHIT gene, a multiple tumor suppressor gene encompassing the carcinogen sensitive Chromosome fragile site, FRA3B Biochim Biophys Acta, 1997, 1332: M65
23 Huebner K, Sozzi G, Brenner C, Pierotti MA, et al. FHIT loss in lung cancer: diagnostic and therapeutic implications. Adv Oncol, 1999, 15:3
24 Boldog FL, Geminill RM, West J, et al. Chromosome 3pl4 homozygous deletions and sequence analysis of FRA3B. Hum Mol Genet, 1997, 6: 193
25 Nelson HH, Wiencke JK, Gunnl, et al. Chromosome 3pl4 alteration in lung cancer: Evidence that FHIT exon deletion is a target of tobacco carcinogens and asbestos. Cancer Res, 1998, 58: 1804
26 Inoue H, Ishii H, Alder H, et al. Sequence of the FRA3B Common fragile region: implications for the mechanisms of FHIT deletion. Proc Natl Acad Sci USA, 1997, 94: 14584
27 Sozzi G, Tomielli S, Tagliabue E, et al. Absence of FHIT protein in primary lung tumors and cell lines with FHIT gene abnormalities. Cancer Res, 1997, 57: 5207
28 Hadaczok P, Siqrashvili Z, Markiewski M, et al. Absence or reduction
of FHIT expression in most clear cell renal careinomas. Cancer Res, 1998, 58: 2946
29 Mao L, Lee JS, Kurie JM, et al. Clonal genetic alterations in the lungs of current and former smokers. J Natl Cancer Inst, 1997, 89: 857
30 dayman GL, Liu TJ, Overholt SM, et al. Gene therapy for head and neck cancer; comparing the tumor suppressor gene p53 and a cell cycle regulator WAF1/CIP1 (p21) . Arch Otolaryngol. Head Neck Surg, 1996, 122: 489
31 Wang XW, Harris CC, TP53 tumor suppressor gene: clues to molecular carcino genesis and cancer therapy (Review). Cancer Surv, 1996, 28: 169
32 Amalia Vartanian, Ivan Alexandrov, Igor Prudowski, et al. AP_4A induces apoptosis in human caltured cells. FEBS Letter, 1999, 456: 175
33 Zamecnik P, Stephenson M. The role of nucleotides for the function and conformation of enzymes. Munksgoard Copenhagen, 1996． 276
34 Kisselev LL, Just Justesen, Alexey D, et al. Diadenosine oligophosphate (ApnA), a novel class of signalling molecules? FEBS Letters, 1998, 427: 157