Abstract
Purpose: It has be observed previously that the pulmonary metastases of colorectal adenocarcinoma are less responsive to therapy with fluorouracil (FUra) as compared with other sites of metastasis (liver, local). To investigate the basis of this chemoresistance, the levels of thymidylate synthase (TS) mRNA and protein were measured, as TS expression has been shown to be predicted of response to therapy in colorectal cancer. Materials and Methods: Tumors were obtained from 19 patients with metastatic colorectal cancer (12 hepatic and seven pulmonary). TS expression was measured by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and TS protein levels were measured by Western blotting. The presence of TS amplification was assessed by Southern blotting. Levels of p53 protein were determined using immunohistochemistry. Results: TS mRNA expression was shown to be significantly higher in the pulmonary metastases (mean TS/β-actin ratio, 19.7; n = 7) as compared with the hepatic metastases (mean TS/β- actin ratio, 4.7; n = 11) of colorectal cancer. Lower TS expression was observed in patients with hepatic metastases who had received prior FUra versus patients who had not been treated. High levels of TS expression in some samples was associated with low-level (two to three germ copies) increases in TS gene copy numbers and this was observed more frequently in the pulmonary metastatic samples. The increased germ copy numbers occurred both in samples with wild-type p53 and those with mutant p53 tumor-suppressor germ as determined by immunohistochemistry. Conclusion: High levels of TS enzyme may be the basis of the lack of response of pulmonary metastases to FUra treatment.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1465-1469 |
| Number of pages | 5 |
| Journal | Journal of Clinical Oncology |
| Volume | 16 |
| Issue number | 4 |
| State | Published - Apr 1998 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Cancer Research
- Oncology
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Higher levels of thymidylate synthase gene expression are observed in pulmonary as compared with hepatic metastases of colorectal adenocarcinoma. / Gorlick, Richard; Metzger, Ralf; Danenberg, Kathleen D.; Salonga, Dennis; Miles, Joseph S.; Longo, Guiseppe S A; Fu, Jenny; Banerjee, Debabrata; Klimstra, David; Jhanwar, Suresh; Danenberg, Peter V.; Kemeny, Nancy; Bertino, Joseph R.
In: Journal of Clinical Oncology, Vol. 16, No. 4, 04.1998, p. 1465-1469.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Higher levels of thymidylate synthase gene expression are observed in pulmonary as compared with hepatic metastases of colorectal adenocarcinoma
AU - Gorlick, Richard
AU - Metzger, Ralf
AU - Danenberg, Kathleen D.
AU - Salonga, Dennis
AU - Miles, Joseph S.
AU - Longo, Guiseppe S A
AU - Fu, Jenny
AU - Banerjee, Debabrata
AU - Klimstra, David
AU - Jhanwar, Suresh
AU - Danenberg, Peter V.
AU - Kemeny, Nancy
AU - Bertino, Joseph R.
PY - 1998/4
Y1 - 1998/4
N2 - Purpose: It has be observed previously that the pulmonary metastases of colorectal adenocarcinoma are less responsive to therapy with fluorouracil (FUra) as compared with other sites of metastasis (liver, local). To investigate the basis of this chemoresistance, the levels of thymidylate synthase (TS) mRNA and protein were measured, as TS expression has been shown to be predicted of response to therapy in colorectal cancer. Materials and Methods: Tumors were obtained from 19 patients with metastatic colorectal cancer (12 hepatic and seven pulmonary). TS expression was measured by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and TS protein levels were measured by Western blotting. The presence of TS amplification was assessed by Southern blotting. Levels of p53 protein were determined using immunohistochemistry. Results: TS mRNA expression was shown to be significantly higher in the pulmonary metastases (mean TS/β-actin ratio, 19.7; n = 7) as compared with the hepatic metastases (mean TS/β- actin ratio, 4.7; n = 11) of colorectal cancer. Lower TS expression was observed in patients with hepatic metastases who had received prior FUra versus patients who had not been treated. High levels of TS expression in some samples was associated with low-level (two to three germ copies) increases in TS gene copy numbers and this was observed more frequently in the pulmonary metastatic samples. The increased germ copy numbers occurred both in samples with wild-type p53 and those with mutant p53 tumor-suppressor germ as determined by immunohistochemistry. Conclusion: High levels of TS enzyme may be the basis of the lack of response of pulmonary metastases to FUra treatment.
AB - Purpose: It has be observed previously that the pulmonary metastases of colorectal adenocarcinoma are less responsive to therapy with fluorouracil (FUra) as compared with other sites of metastasis (liver, local). To investigate the basis of this chemoresistance, the levels of thymidylate synthase (TS) mRNA and protein were measured, as TS expression has been shown to be predicted of response to therapy in colorectal cancer. Materials and Methods: Tumors were obtained from 19 patients with metastatic colorectal cancer (12 hepatic and seven pulmonary). TS expression was measured by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and TS protein levels were measured by Western blotting. The presence of TS amplification was assessed by Southern blotting. Levels of p53 protein were determined using immunohistochemistry. Results: TS mRNA expression was shown to be significantly higher in the pulmonary metastases (mean TS/β-actin ratio, 19.7; n = 7) as compared with the hepatic metastases (mean TS/β- actin ratio, 4.7; n = 11) of colorectal cancer. Lower TS expression was observed in patients with hepatic metastases who had received prior FUra versus patients who had not been treated. High levels of TS expression in some samples was associated with low-level (two to three germ copies) increases in TS gene copy numbers and this was observed more frequently in the pulmonary metastatic samples. The increased germ copy numbers occurred both in samples with wild-type p53 and those with mutant p53 tumor-suppressor germ as determined by immunohistochemistry. Conclusion: High levels of TS enzyme may be the basis of the lack of response of pulmonary metastases to FUra treatment.
UR - http://www.scopus.com/inward/record.url?scp=0031947357&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031947357&partnerID=8YFLogxK
M3 - Article
C2 - 9552053
AN - SCOPUS:0031947357
VL - 16
SP - 1465
EP - 1469
JO - Journal of Clinical Oncology
JF - Journal of Clinical Oncology
SN - 0732-183X
IS - 4
ER -