| 1. |
- Killela, Patrick J., et al.
(författare)
-
TERT promoter mutations occur frequently in gliomas and a subset of tumors derived from cells with low rates of self-renewal
- 2013
-
Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 110:15, s. 6021-6026
-
Tidskriftsartikel (refereegranskat)abstract
- Malignant cells, like all actively growing cells, must maintain their telomeres, but genetic mechanisms responsible for telomere maintenance in tumors have only recently been discovered. In particular, mutations of the telomere binding proteins alpha thalassemia/mental retardation syndrome X-linked (ATRX) or death-domain associated protein (DAXX) have been shown to underlie a telomere maintenance mechanism not involving telomerase (alternative lengthening of telomeres), and point mutations in the promoter of the telomerase reverse transcriptase (TERT) gene increase telomerase expression and have been shown to occur in melanomas and a small number of other tumors. To further define the tumor types in which this latter mechanism plays a role, we surveyed 1,230 tumors of 60 different types. We found that tumors could be divided into types with low (<15%) and high (>= 15%) frequencies of TERT promoter mutations. The nine TERT-high tumor types almost always originated in tissues with relatively low rates of self renewal, including melanomas, liposarcomas, hepatocellular carcinomas, urothelial carcinomas, squamous cell carcinomas of the tongue, medulloblastomas, and subtypes of gliomas (including 83% of primary glioblastoma, the most common brain tumor type). TERT and ATRX mutations were mutually exclusive, suggesting that these two genetic mechanisms confer equivalent selective growth advantages. In addition to their implications for understanding the relationship between telomeres and tumorigenesis, TERT mutations provide a biomarker that may be useful for the early detection of urinary tract and liver tumors and aid in the classification and prognostication of brain tumors.
|
|
| 2. |
|
|
| 3. |
- Davis, Faith G, et al.
(författare)
-
Issues of diagnostic review in brain tumor studies : from the brain tumor epidemiology consortium
- 2008
-
Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - : American Association for Cancer Research (AACR). - 1055-9965 .- 1538-7755. ; 17:3, s. 484-489
-
Tidskriftsartikel (refereegranskat)abstract
- Epidemiologists routinely conduct centralized single pathology reviews to minimize interobserver diagnostic variability, but this practice does not facilitate the combination of studies across geographic regions and institutions where diagnostic practices differ. A meeting of neuropathologists and epidemiologists focused on brain tumor classification issues in the context of protocol needs for consortial studies (http://epi.grants.cancer.gov/btec/). It resulted in recommendations relevant to brain tumors and possibly other rare disease studies. Two categories of brain tumors have enough general agreement over time, across regions, and between individual pathologists that one can consider using existing diagnostic data without further review: glioblastomas and meningiomas (as long as uniform guidelines such as those provided by the WHO are used). Prospective studies of these tumors benefit from collection of pathology reports, at a minimum recording the pathology department and classification system used in the diagnosis. Other brain tumors, such as oligodendroglioma, are less distinct and require careful histopathologic review for consistent classification across study centers. Epidemiologic study protocols must consider the study specific aims, diagnostic changes that have taken place over time, and other issues unique to the type(s) of tumor being studied. As diagnostic changes are being made rapidly, there are no readily available answers on disease classification issues. It is essential that epidemiologists and neuropathologists collaborate to develop appropriate study designs and protocols for specific hypothesis and populations.
|
|
| 4. |
- Kato, Yukinari, et al.
(författare)
-
GMab-1, a high-affinity anti-3'-isoLM1/3',6'-isoLD1 IgG monoclonal antibody, raised in lacto-series ganglioside-defective knockout mice
- 2010
-
Ingår i: Biochemical and biophysical research communications. - : Elsevier BV. - 1090-2104 .- 0006-291X. ; 391:1, s. 750-5
-
Tidskriftsartikel (refereegranskat)abstract
- The lacto-series gangliosides 3'-isoLM1 and 3',6'-isoLD1 have been identified as tumor-associated antigens whose formation is initiated by the Lc3-synthase. Until now, high-affinity IgG monoclonal antibodies (mAbs) against 3'-isoLM1 and 3',6'-isoLD1, which are highly expressed in gliomas, have not been developed, although mAbs against lacto-series gangliosides are powerful tools for functional studies. We previously produced the Lc3-synthase gene beta3Gn-T5 knockout mice. In this study, we immunized beta3Gn-T5 knockout mice with 3'-isoLM1/3',6'-isoLD1 and produced the anti-3'-isoLM1/3',6'-isoLD1 mAb GMab-1, of the IgG(3) subclass, which should be useful for functional analysis of lacto-series gangliosides and for antibody-based therapy of gliomas.
|
|
| 5. |
- Kuan, Chien-Tsun, et al.
(författare)
-
Multiple phenotypic changes in mice after knockout of the B3gnt5 gene, encoding Lc3 synthase-a key enzyme in lacto-neolacto ganglioside synthesis
- 2010
-
Ingår i: BMC Developmental Biology. - 1471-213X. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- Background Ganglioside biosynthesis occurs through a multi-enzymatic pathway which at the lactosylceramide step is branched into several biosynthetic series. Lc3 synthase utilizes a variety of galactose-terminated glycolipids as acceptors by establishing a glycosidic bond in the beta-1,3-linkage to GlcNaAc to extend the lacto- and neolacto-series gangliosides. In order to examine the lacto-series ganglioside functions in mice, we used gene knockout technology to generate Lc3 synthase gene B3gnt5-deficient mice by two different strategies and compared the phenotypes of the two null mouse groups with each other and with their wild-type counterparts. Results B3gnt5 gene knockout mutant mice appeared normal in the embryonic stage and, if they survived delivery, remained normal during early life. However, about 9% developed early-stage growth retardation, 11% died postnatally in less than 2 months, and adults tended to die in 5-15 months, demonstrating splenomegaly and notably enlarged lymph nodes. Without lacto-neolacto series gangliosides, both homozygous and heterozygous mice gradually displayed fur loss or obesity, and breeding mice demonstrated reproductive defects. Furthermore, B3gnt5 gene knockout disrupted the functional integrity of B cells, as manifested by a decrease in B-cell numbers in the spleen, germinal center disappearance, and less efficiency to proliferate in hybridoma fusion. Conclusions These novel results demonstrate unequivocally that lacto-neolacto series gangliosides are essential to multiple physiological functions, especially the control of reproductive output, and spleen B-cell abnormality. We also report the generation of anti-IgG response against the lacto-series gangliosides 3'-isoLM1 and 3',6'-isoLD1.
|
|
