Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Prognostic significance of apoptosis related gene family bcl-2 in human breast cancer


Objective: To study the prognostic effect of bcl-2 oncogene and its gene family members bax, bcl-x expression in breast cancer patients. Methods: Expression of bcl-2, bax proteins in 91 human breast cancer tissue sections were studied by immunohistochemical method, bcl-x1 mRNA expression in frozen tissues from 16 breast cancer patients were detected using Northern blot method. Results: bcl-2 protein positivity was found in 60/91 (65.9%) patients, and bax positivity 59/91 (64.8%). bcl-2 and bax expression levels were associated with apoptotic index(AI), histological grade, axillary lymph node metastasis, postoperative local recurrence and metastasis, bcl-2 expression was related to ER positivity. In univariate analysis for disease free survival (DFS), bcl-2 and bax protein levels, and Al were all found to have prognostic value. The result of Cox’s model multivariate analysis showed that bcl-2 protein level was an independent prognostic factor. In 16 frozen breast cancer tissues, 8/16(50%) had higher level of bcl-x1 mRNA, which showed correlation with bcl-2 protein expression and axillary lymph node metastasis. Conclusion: The findings indicate that dysregulated expressions of bcl-2, bax and bcl-x1 apoptosis-related genes, suggestive of serious deregulation of apoptotic process, may contribute to the biologic aggressiveness of breast cancer, bcl-2 protein is an independent indicator of prognosis in breast cancer patients.

This is a preview of subscription content, log in to check access.


  1. [1]

    Reed JC. bcl-2 and the regulation of programmed cell death. J Cell Biol 1994; 124:1.

  2. [2]

    Wu J, Shao ZM, Jiang M, et al.In situ DNA labeling apoptosis in breast carcinoma as related prognosis. Chin J Oncol 1997; 19:100.

  3. [3]

    Elston D, Ellis KL. Pathology prognostic factors in breast cancer. I. The value of histological grade in breast cancer experience from a large study with long-term follow-up. Histopathol 1991; 19:403.

  4. [4]

    Chomczynski P, Sacchi N. Single step Rna isolation by acid guanidiom thiocyarate-phenol chloroform extraction. Anal Biochem 1987; 162:156.

  5. [5]

    Gasparini G, Barbareschi M, Doglioni C, et al. Expression of bcl-2 protein predicts efficacy of adjuvant treatments in operable node-positive breast cancer. Clin Cancer Res 1995; 1:189.

  6. [6]

    Liponen P, Pietilainen T, Kosma VM, et al. Apoptosis suppressing protein bcl-2 is expressed in well differentiated breast carcinomas with favourable prognosis. J Pathol 1995; 177:49.

  7. [7]

    Bukholm 1K, Nesland JM, Karesen R, et al. Interaction between bcl-2 and p21(WAF1/CIP1) in breast carcinomas with wild-type p53. Int J Cancer 1997; 73:38.

  8. [8]

    Krajewski S, Blomqvist C, Franssila K, et al. Reduced expression of proapoptotic gene bax is associated with poor response rates to combination chemotherapy and shorter survival in women with metastatic breast adenocarcinoma. Cancer Res 1995; 55:447.

  9. [9]

    Kapranos N, Karaiosifidi H, Valavanis C, et al. Prognostic significance of apoptosis related proteins bcl-2 and bax in node-negative breast cancer patients. Anticancer Res 1997; 17:2499.

  10. [10]

    Olopade OI, Adeyanju MO, Safa AR, et al. Overexpression of bcl-x protein in primary breast cancer is associated with high tumor grade and nodal metastases. Cancer J Sci Amer 1997; 3:230.

Download references

Author information

Correspondence to Zhi-min Shao.

Additional information

This work was supported by the National Natural Science Foundation of China (No. 39670803).

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Wu, J., Lu, J., Shao, Z. et al. Prognostic significance of apoptosis related gene family bcl-2 in human breast cancer. Chin J Cancer Res 12, 5–9 (2000).

Download citation

Key words

  • Breast cancer
  • Prognosis
  • Apoptosis
  • Oncogene