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本帖最后由 pujixing 于 2014-9-22 17:17 编辑 + t# B6 O/ n N5 K
' ^0 T& N; X1 w8 k2 F2 A3 }2 K- f8 Z回复 knowtumor 的帖子+ V( o2 h5 P, \/ f
0 m' M8 [" v" D. e, f8 X9 c4 c诚如楼上所说，要找到一个能代表所有肿瘤的抽象的肿瘤是有很大困难的。但如果去重温一下Weinberg和Hanahan所写的两篇Cancer Hallmark（2000年和2011年发表于Cell杂志）的文章后，应该会有一个较为清晰的轮廓。在前文中说描述的是畸胎瘤的特殊性。首先，畸胎瘤这个概念是个非常宽松的定义，其实其来源是非常多样的（具体种类在此不细述，可在网上找到很多资料）。畸胎瘤中绝大多数是成熟的，或说是良性的，只有很小的比例是恶性的，而恶性的这部分才是真正的cancer。癌症的致命性并不在于其无限生长的特性，而是转移性。在这一点来说，畸胎瘤这个马群里的绝大多数马，都不具有这种代表性（malignancy中最重要的部分）。
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s! d3 f+ ^9 d/ L1 I因为目前在下所能认识到的范围内，癌细胞可变为正常细胞的观点并不是主流观点，而且在下对这个有趣的问题的确心存很多疑问。也或许是遇到一些超前的但没来得及正确认识到的观点（历史上的确有一些案例表明某些超前的理论在初期并没有得到应有的承认，比如转座子，比如HPV和宫颈癌的关系等等）。在此情形下，Know Tumor大侠可否和我们分享一下畸胎瘤（良性畸胎瘤还是恶性？）/肝癌细胞（癌细胞存活状况？）移植变为正常的文献，以及豹蛙（豹蛙肾癌细胞移植后没有影响其生育能力，但是否就终止了癌症发生呢？）的文献。
6 K8 C9 i% n* _% _, e' L% A看是否能从中找出我们没有提及的重要细节呢？
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# m6 r9 l8 G6 Q这里有篇文章可参考关于移植畸胎瘤细胞的一些引起注意的事实（teratoma v.s teratocarcinoma）：
* l! A. p- r/ o1 u: X# x# SCorrespondence
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6 K) P y! B( ?& [& aNature Biotechnology 25, 1212 (2007)
% ]9 N$ W& W8 ~, X# sdoi:10.1038/nbt1107-1212a
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/ [* k- a6 F Q; d- Z- FThe terminology of teratocarcinomas and teratomas7 K; }$ C( q9 c, X
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Ivan Damjanov1 & Peter W Andrews2
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From our point of view, most of the problems and controversies mentioned in this correspondence have arisen from the inconsistent usage of the terms teratoma and teratocarcinoma by many scientists working in this field. Thus, we encourage the editors of Nature Biotechnology to standardize the terminology, at least for human embryonic stem (ES) cell–derived xenografts.% |' R. S6 k" z7 n2 a) n1 }2 l
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In our view, the term teratocarcinoma should be used only for malignant tumors, which in this context are malignant by virtue of the continued presence of stem cells—the embryonal carcinoma (EC) cells1. EC cells, as suggested by almost all studies on mouse- and human-derived cells, are the malignant equivalents or cognates of ES cells2. Any pathologist trained to identify human EC cells should be able to distinguish malignant teratocarcinomas from benign teratomas, which are defined as tumors composed only of somatic tissues and devoid of EC cells. In an experimental setting, the malignancy of a tumor due to the presence of morphologically identifiable EC cells can be tested by re-transplantation to a new host.
6 m6 l K7 }' `3 {The distinction between teratomas and teratocarcinomas is crucial, especially for the future usage of ES cells in human medicine. [[[[[[Using xenografting as an essential preclinical safety control, one could predict that the ES cell lines that form only teratomas are 'benign' or 'safe' for human usage, whereas the cell lines that produce teratocarcinomas are 'malignant' and not safe for injection into humans3]]]]]]. Thus, we would discourage the indiscriminate usage of terms 'teratoma' and 'teratocarcinoma', even though in the past some eminent scientists have used those term interchangeably and even as synonyms. Previous imprecision is, in our opinion, not a valid justification for future use of a confusing terminology., e- _ \3 `7 `& O" |
& |, a5 c P& _A minor but not insurmountable problem pertains to the usage of 'teratocarcinoma' for tumors produced from human ES cells. Even though the term 'teratocarcinoma' has been used as a synonym for malignant teratoma in mice for more than four decades, most leaders in human pathology have consistently refused to accept it. In the recent consensus book on human testicular tumors compiled by the experts of the World Health Organization (WHO; Geneva, Switzerland)4, the term teratocarcinoma is mentioned only in passing for the animal model of human germ cell tumors. Because the work on human ES cells is, in a sense, a continuation of the experiments first performed on mouse ES cells and teratocarcinoma-derived EC cells, we feel that the term 'teratocarcinoma' will be more readily accepted by laboratory researchers than diagnostic pathologists. At least it is less cumbersome than the WHO-recommended term “mixed embryonal carcinoma and teratoma” or indeed the British classification “malignant teratoma intermediate4”.
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Nature Biotechnology 25, 1212 (2007) & d! H* F) e$ }1 N
doi:10.1038/nbt1107-1212b' f1 j" I. Z5 i1 G2 V6 |
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0 N2 E* n* S) N( R1 u! gResponse to The terminology of teratocarcinomas and teratomas
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/ W- w9 ? B Y4 d8 j- WIntroduction
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; \, r, e& G! }Nature Biotechnology responds:
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A survey of the literature indicates no consensus on how to distinguish the terms 'teratoma' and 'teratocarcinoma'. The term 'teratocarcinoma' is used as a synonym for human tumors clinically known as “teratoma with embryonal carcinoma” (according to the World Health Organization) or “teratoma intermediate” (according to the British classification of germ cell tumors). Some pathologists include these tumors in the group of testicular 'nonseminomas' (also known as 'nonseminomatous germ cell tumors (NSGCT)') or use imprecise terms, such as 'malignant teratoma'. The somatic tissues in teratocarcinoma may be fully differentiated (equivalent to adult tissue) or only partially differentiated (corresponding to immature tissues in fetal organs).; n1 q' W. ^7 T5 C# _3 P: k+ J
$ S, a0 d# A8 r u. D& lOn the basis of the above exchange and after expert consultation, Nature Biotechnology will adopt the term 'teratocarcinoma' to describe malignant tumors comprising both somatic tissues and undifferentiated malignant stem cells, identifiable as EC cells. EC cells are malignant equivalents of ES cells. Human EC cells should be identifiable microscopically according to the pathologic and immunohistochemical criteria used to identify human EC cells in malignant germ cell tumors of the ovary or testis or extragonadal sites. In an experimental setting, the malignancy of a tumor due to the presence of morphologically identifiable undifferentiated EC cells may be defined by their ability to form a new tumor after transplantation to a new host.) X( F5 ~8 }' d( l9 i k+ N/ o
; K: F A1 U7 w6 H5 F5 q& LWe will apply the term 'teratoma' only to tumors composed of normal, 'benign' somatic tissue and their immature (fetal) precursors derived from more than one of the three embryonic germ layers (ectoderm, mesoderm and endoderm). Teratomas comprising nonproliferating somatic tissue may be further labeled as 'benign', 'mature' or 'fully differentiated'. Teratomas composed of immature, proliferating fetal-like tissues may be labeled 'immature'.6 p5 F) Q/ g9 e& ~) j) b
, V6 B' |; t+ i8 F0 ]& E9 |It should be noted that almost all tumors produced in immunosuppressed mice from xenografted human ES cells have proven to be teratomas. Some data suggest that teratocarcinomas may occasionally be produced from human ES cells upon xenografting, but these tumors have not been fully documented. i; c2 z8 Z. p" \6 G! e
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以上拙见欢迎指正。 |
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发表于 2013-6-3 00:04
发表于 2014-9-22 17:33
