RESUMO
In breast cancer, cytochrome P450 (CYP) metabolizes both endogenous substrates (i.e. estradiol) and exogenous substrates (i.e. anticancer drugs), which is associated not only with tumor development and progression but also with efficacy of cancer treatment. Therefore, we examined the expression of CYPs (CYP2A6, CYP1B1 and CYP3A) and p53 in specimens from 34 Japanese patients with breast cancer by immunohistochemistry. The expression of CYP3A was not detected in the 34 cases. CYP2A6 was detected only in one specimen (2.9%). Twenty-eight specimens (82.4%) showed positive signals for CYP1B1 expression. Eight of 34 (23.5%) were positive for p53 expression. Positive rate of CYP1B1 in stage I disease (100%) was statistically higher than that in stage II - IV disease (70.0%). Positive rate of p53 was 21.4% (6/28) in CYP1B1-positive cases and 33.3% (2/6) in CYP1B1-negative cases. There was no significant relationship between CYP1B1 expression and p53 expression. In conclusion, the expression of CYP3A in breast cancer may be less frequent in Japanese population although the expression of CYP3A has been reported in 20% of breast cancer in Caucasian, suggesting that the CYP3A expression in breast cancer may be dependent on ethnic groups. Since CYP3A is involved in the conversion of tamoxifen to its metabolites, the variation of the CYP3A expression in breast cancer tissues among ethnic groups might cause differences in the efficacy of tamoxifen.
Assuntos
Neoplasias da Mama/enzimologia , Sistema Enzimático do Citocromo P-450/metabolismo , Proteína Supressora de Tumor p53/análise , Adulto , Idoso , Hidrocarboneto de Aril Hidroxilases/metabolismo , Neoplasias da Mama/metabolismo , Citocromo P-450 CYP1B1 , Citocromo P-450 CYP2A6 , Citocromo P-450 CYP3A/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Estrogênios/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Oxigenases de Função Mista/metabolismo , Tamoxifeno/metabolismoRESUMO
UNLABELLED: Serum copper (Cu), zinc (Zn) the Cu/Zn ratio (Cu/Zn) and selenium (Se) were evaluated in 84 patients with non-small cell lung cancer (NSCLC) before surgery. Serum carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC) and sialyl Lewis X-i antigen (SLX) levels were also determined in the same cases. The cut-off values of Cu, Zn and Se were established to create two categories with equal numbers of patients. We investigated the clinical and prognostic usefulness of assays of serum trace elements (Cu, Zn, Cu/Zn and Se) and compared levels of serum trace elements and serum tumor markers (CEA, SCC and SLX) in NSCLC patients. Furthermore, we evaluated the usefulness of serum trace elements, when compared with tumor markers, in assessing prognosis for NSCLC. IN CONCLUSION: (1) a preoperative increase in Cu/Zn level predicted tumor progression more effectively than changes in Cu or Zn levels; (2) Se levels seemed to vary with age, but there was no relationship between Se level and disease stage; (3) the measurement of Cu/Zn was useful for assessing both prognosis and extent of the disease in NSCLC patients, similar to the measurement of serum tumor markers such as CEA; and (4) the measurement of the Cu/Zn had prognostic significance, but was inferior to disease stage in predicting outcome. Cu and Zn in serum are storable and the determination of Cu/Zn level is so simple and inexpensive that it can be helpful in determining clinical stages and predicting the prognoses of NSCLC patients.